Classification and principle of the touch screen

Typically, the touch screen system touch detection sensor components and touch screen controller part of the device. Former collect the user's touch and transferred to the controller, the latter by processing the received information, the user's touch position, and location information sent to the upper layer of the host, while receiving control commands sent by the host and to executed.
The primary segment of the touch screen
Distinguished from the technical principles, the touch screen can be divided into four basic types: infrared touch screen technology, surface acoustic wave touch screen, resistive touch screen, capacitive touch screen. The following will be more than four touch-screen technology brief introduction.
1, infrared touch screen technology
The touch screen mounted on the outer frame of the touch screen by the infrared transmitting and receiving device comprising. The device emitting infrared detector is formed in the surface of the screen mesh, any object can change the contact infrared touch detection. Infrared touch screen is not current, voltage and electrostatic interference, suitable for the conditions of poor working conditions, low price, easy to install, fast response. Infrared applications now been widely, and are generally used for large-scale equipment, such as TV moderator touch TV, life in general, high accuracy, multi-point, light transmittance, up to 100%.TFT LCD Misplays
2, the surface acoustic wave touch screen
Surface acoustic wave is the mechanical wave propagation along the surface of the medium. Such touch screen is composed by a touch screen, a sound generator, a reflector and a sonic receiver. Wherein the acoustic wave generator to produce a high-frequency sound waves across the surface of the screen, when the touch of the finger, the electric shock on the acoustic wave is blocked, thereby determining the coordinates of the sound wave receiving position. Surface acoustic wave touch screen is not the impact of environmental factors such as temperature, humidity, high resolution, excellent scratch resistance, long life, good light transmittance, there is no drift, the surface is not afraid plan, the disadvantage is afraid of the water and oil , dirty to safeguard.
3, the resistive touch screen
Resistive touch screen is a display surface to match the multi-layer composite film. As primary structure with a layer of glass, coated with a layer of a transparent conductive layer (ITO, indium oxide), and the upper layer is then covered with a layer of scratch-resistant plastic layer, and its inner surface is also coated with a layer of ITO, four lines and eight lines The touch screen consists of two layers of transparent resistive material with the same surface resistance, five-wire and 7-wire touch screen, which usually consists of a resistive layer and a conductive layer between two conductive layers, many of the small (less than one thousandth of an inch ) transparent separation point separating them. When the pressure exerted on the touch screen surface (such as through the pen tip or finger pressed) is sufficiently large, the contact will be generated between the top and bottom. All resistive touch screen using a voltage divider principle to generate a voltage representative of the X coordinate and Y coordinate.color lcd display module